[Video] Q26: To determine the mean number of children per household in a community, tabitha surveyed 20 families at a playground. for the 20 families surveyed, the mean number of children per household was 2.4. which of the following statements must be true?

Explanation for Question 26 From the Math (Calc) Section on the Official Sat Practice Test 8

So in this question, we are told about Tabitha who samples 2 a 20 families at a playground to find the mean number of children per 3 household and the community. So the important thing to know here is that we're 4 sampling the families from a playground and of the 20 families. 5 We had a mean of 2.4 and we need to figure out which are 6 true. So now a says the mean number of children per household in the 7 community is 2.4. 8 And so a is slightly questionable, 9 right? Because we're saying here that the mean of the community is 2.4, 10 but Tamica didn't actually sample the whole community. 11 She just sampled the playground. 12 Right? And so the playground and the community as a whole might be different. 13 So for that reason, we know that a can't be right, 14 because Tabitha would be generalizing her results over a too broad of an audience. 15 Now B says a determination about the mean number of children per household in 16 the community should not be made because the sample size is too small. 17 And so this might be true, 18 right? Because she only sampled 20 families, 19 but we actually don't know how many families are in the community, 20 right? Maybe there aren't a lot of families in the community and 20 is 21 a really large number in twenties, almost all of them. 22 So we actually can't say anything about B either because we don't know the 23 size of the community. So we don't know how good or bad her sample 24 sizes. Now C tells us that the sampling method 25 is flawed ...